1. Field of the Invention
The present invention relates to an inkjet printhead and, more particularly, to an inkjet printhead adaptive for a single-color inkjet printing.
2. Description of Related Art
In the present technologies of inkjet printhead, the best and the most effective way for improving the printing resolution and printing speed is achieved by increasing the quantity of heating elements on a inkjet chip directly, i.e. by increasing the quantity of nozzles. Traditionally, the controlling of the conventional heating elements is achieved by controlling a corresponding heating element through a single control contact.
With reference to FIG. 1, a schematic view illustrating the conventional circuit structure for controlling a heating element for heating is shown. As illustrated in FIG. 1, a heating element 10 is connected in-between a driving control terminal 11 and a switch element 12, and receives a voltage signal P from the driving control terminal 11. The switching element 12 connects in-between a control terminal 13 and a ground terminal 14, wherein the control terminal 13 receives an address signal A for controlling the on-off of the switching element 12. The switching element 12 is turned on when the address signal A received by the control terminal 13 is relatively logically high. In the meantime, the voltage signal P provides an electrical energy to the heating element 10, and printing the ink flowing over the heating element 10 onto a printing carrier through corresponding nozzles (not shown in the figure). On the contrary, the switching element 12 is turned off when the address signal A received by the control terminal 13 is relatively logically low. In the meantime, the voltage signal P stops supplying electrical energy to the heating element 10, so that the heating element 10 stops heating process. Therefore, the ink-jetting cannot be achieved.
However, in the aforementioned method for controlling the heating of a heating element, the number of heating elements has to be increased if the printing resolution and printing speed is increased. The number of control terminals needs to be correspondingly increased as well to control each heating element respectively. For instance, 20 control terminals is required for matching 20 address signals A which control the heating of an inkjet printhead, this leads to an increase in size of the whole wiring region of an inkjet chip (not shown in the figure) and an increase of the practical area for disposing of the inkjet chip. Moreover, the cost for manufacturing increases accordingly. The wiring region described above is the rest region except for ink-supplying flow channels.
Furthermore, in order to decrease the quantity of control terminals, a method for controlling the operation of heating element by N-MOS element is introduced correspondingly. However, the quantity of the corresponding control terminals should be increased if further increasing of the quantity of heating elements is desired. Therefore, methods for controlling by C-MOS are then introduced for solving the problem of the size-enlargement of the inkjet chip area that caused by the augmentation on wiring region when the quantity of control terminals increases. However, these methods still cannot be popularized since the cost for manufacturing C-MOS is much higher than that of N-MOS.
Therefore, a method capable of improving the shortcomings of inkjet printheads described above is quite in demand in this technical field.